In certain railroad operations, such as, in a classification processing yard, the railway cars or vehicles of incoming trains are sorted or classified in accordance with consist and destination in a given one of a plurality of class or receiving tracks. In hump types of classification yards, it is necessary to control the velocity or speed of the free-rolling vehicles by suitable braking apparatus. Generally, the braking apparatus takes the form of power operated frictional car retarders having braking bars which engage and grip the sides of the passing wheels of the humped railway vehicles. It will be appreciated that the amount of retardation or braking effort which is exerted on the passing wheels by the ar retarder is dependent upon the rollability and the distance that the humped vehicle or cut of vehicles have to travel to safely couple with the foregoing vehicle in the appropriate class track. It has been found that the most effective retardation occurs when the frictional braking force is applied to a relatively high point on the sides of the car wheels. The ensuing benefits of higher wheel contact braking results in the ability to construct and utilize shorter car retarders in the classification yards. It will the car retarder not only reduces the initial manufacturing costs but also results in the more economical use of the available space of the yard since the required length of the approach track is proportionally reduced. Further, it has been found that the leading edges, corner sill portions, or side ladders on locomotives and/or vehicles hit the upper levers and cause damage to the vehicles and retarders. Further, since some humped cars were unable to clear and freely pass through the existing car retarders, the amount of retardation was not always accurately controlled. Thus, it would be highly advantageous to provide a low-profile car retarder to allow the unimpeded passage of the locomotives and particularly, the humped cars. An additional problem in conventional braking apparatus resides in the difficulty in making the necessary adjustments for brake shoe wear and lever stopping. Thus, it is desirable to provide a simple time-saving method of brake shoe and stop adjustment.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a new and improved railway braking apparatus for effectively retarding railway cars.
Still another object of this invention is to provide a unique low-profile railway car retarder which allows the free unimpeded passage of humped vehicles.
Still a further object of this invention is to provide a novel frictional-type of gripping railway braking apparatus which more effectively retards passing vehicles by having the brake shoes engage the sides of the wheels at a relatively higher level.
Yet another object of this invention is to provide an improved railway car retarder which is readily adjusted for compensating for brake shoe wear.
Yet a further object of this invention is to provide a new pneumatic operated car retarder having a pair of braking bars disposed parallel and on opposite sides of a track rail, an upper and a lower pivotal lever, each of the upper and lower pivotal levers having a platform portion for carrying a respective one of the pair of braking bars and having a laterally extending arm, a pneumatic piston-cylinder actuator, the piston of the pneumatic piston-cylinder actuator pivotally connected to the outer extremity of the laterally extending arm of the lower pivotal lever, the cylinder of the pneumatic piston-cylinder actuator pivotally connected to the outer extremity of the laterally extending arm of the upper pivotal lever, the height of the pivotal connection of the cylinder with the upper pivotal lever is substantially at the same level as the top of the track rail so that a railway vehicle is permitted to freely pass through the car retarder, and the pneumatic piston-cylinder actuator lifts the upper pivotal lever and depresses the lower pivotal lever for moving one pair of braking bars to a closed braking position when pressure is supplied to the pneumatic piston-cylinder actuator so that the pair of braking bars engage the opposite sides of the vehicle wheels at a relatively high point to exert an increased amount of retardation on the passing vehicle.
An additional object of this invention is to provide a new and improved railway car retarder which is economical in cost, simple in construction, dependable in service, easy to maintain, durable in use, efficient in operation, and facile to repair.